...Since the late 1970s China has moved from a closed, centrally planned system to a more market-oriented one that plays a major global role - in 2010 China became the world's largest exporter. Reforms began with the phasing out of collectivized agriculture, and expanded to include the gradual liberalization of prices, fiscal decentralization, increased autonomy for state enterprises, creation of a diversified banking system, development of stock markets, rapid growth of the private sector, and opening to foreign trade and investment. China has implemented reforms in a gradualist fashion. In recent years, China has renewed its support for state-owned enterprises in sectors it considers important to "economic security," explicitly looking to foster globally competitive national champions. After keeping its currency tightly linked to the US dollar for years, in July 2005 China revalued its currency by 2.1% against the US dollar and moved to an exchange rate system that references a basket of currencies. From mid 2005 to late 2008 cumulative appreciation of the renminbi against the US dollar was more than 20%, but the exchange rate remained virtually pegged to the dollar from the onset of the global financial crisis until June 2010, when Beijing allowed resumption of a gradual appreciation. The restructuring of the economy and resulting efficiency gains have contributed to a more than tenfold increase in GDP since 1978. Measured on a purchasing power parity (PPP) basis that adjusts for price differences, China in 2012 stood as the second-largest economy in the world after the US, having surpassed Japan in 2001...
... The dollar values of China's agricultural and industrial output each exceed those of the US; China is second to the US in the value of services it produces. Still, per capita income is below the world average. The Chinese government faces numerous economic challenges, including: (a) reducing its high domestic savings rate and correspondingly low domestic demand; (b) sustaining adequate job growth for tens of millions of migrants and new entrants to the work force; (c) reducing corruption and other economic crimes; and (d) containing environmental damage and social strife related to the economy's rapid transformation...
... Economic development has progressed further in coastal provinces than in the interior, and by 2011 more than 250 million migrant workers and their dependents had relocated to urban areas to find work. One consequence of population control policy is that China is now one of the most rapidly aging countries in the world. Deterioration in the environment - notably air pollution, soil erosion, and the steady fall of the water table, especially in the North - is another long-term problem. China continues to lose arable land because of erosion and economic development...

GDP (purchasing power parity):

$12.61 trillion (2012 est.)
country comparison to the world: 3
$11.7 trillion (2011 est.)
$10.7 trillion (2010 est.)
note: data are in 2012 US dollars
GDP (official exchange rate):
$8.227 trillion
note: because China's exchange rate is determine by fiat, rather than by market forces, the official exchange rate measure of GDP is not an accurate measure of China's output; GDP at the official exchange rate substantially understates the actual level of China's output vis-a-vis the rest of the world; in China's situation, GDP at purchasing power parity provides the best measure for comparing output across countries (2012 est.)

-country comparison to the world: 20
...Labor force:
-798.5 million
country comparison to the world: 1
note: by the end of 2012, China's population at working age (15-64 years) was 1.0040 billion
Labor force - by occupation:

-13.4%
note: in 2011, China set a new poverty line at RMB 2300 (approximately US $3,630)
(2011)
...Household income or consumption by percentage share:
-lowest 10%: 3.5%
-highest 10%: 15%
..note: data are for urban households only (2008)

frequent typhoons (about five per year along southern and eastern coasts); damaging floods; tsunamis; earthquakes; droughts; land subsidence
volcanism: China contains some historically active volcanoes including Changbaishan (also known as Baitoushan, Baegdu, or P'aektu-san), Hainan Dao, and Kunlun although most have been relatively inactive in recent centuries

Environment - current issues:

-air pollution (greenhouse gases, sulfur dioxide particulates) from reliance on coal produces acid rain; China is the world's largest single emitter of carbon dioxide from the burning of fossil fuels; water shortages, particularly in the north; water pollution from untreated wastes; deforestation; estimated loss of one-fifth of agricultural land since 1949 to soil erosion and economic development; desertification; trade in endangered species

5.2% of GDP (2011)
country comparison to the world: 135
-Physicians density:

1.456 physicians/1,000 population (2010)
Hospital bed density:

3.8 beds/1,000 population (2011)
- Drinking water source:

improved:
urban: 98% of population
rural: 85% of population
total: 91% of population
unimproved:
urban: 2% of population
rural: 15% of population
total: 9% of population (2010 est.)
Sanitation facility access:

improved:
urban: 74% of population
rural: 56% of population
total: 64% of population
unimproved:
urban: 26% of population
rural: 44% of population
total: 36% of population (2010 est.)
HIV/AIDS - adult prevalence rate:

0.1% (2009 est.)
country comparison to the world: 116
HIV/AIDS - people living with HIV/AIDS: